Method of sterilizing canned goods



April 15, 1930. A. R. THOMPSON METHOD OF STER ILIZING CANNED GOODS Filed Sept. 29, 1920 3 Sheets-Sheet 1 IN V EN TOR j/Jul- .4 ,ZQ

, WITNESS A TTORNE YS April 15, 1930.

A. R. THOMPSON METHOD OF STERILIZING CANNED GOODS Filed Sept. 29, 1920 5 Sheets-Sheet 2 INVENTOR WITNESS ATTORNEYS April 15, 1930'. A, R. THOMPSON METHOD OF STERILIZING CANNED GOODS Filed Sept. 29, 1920 5 Sheets-Sheet IN VEN TOR 74, AW w:

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1' WITNESS A TTORNE YS Patented Apr. 15, 1930 UNITED STATES PATENT oer-Ice ALBERT R. THOMPSON, OF SAN JOSE, CALIFORNIA, ASSIGNOR TO ANDERSON-BARN- GROVER MFG. (30., OF SAN JOSE, CALIFORNIA, A CORPORATION OF CALIFORNIA c METHOD OF STERILIZING CANNED GOODS Application filed September 29, 1920. Serial No. 413,588.

My invention relates to the art of sterilizing canned goods. Commodities, according to. their nature, require different temperatures, and .diiferent times of cook.

Also many commodities after being cooked in their cans require to be cooled as part of the sterilizing process. Cooking under pressure greater than atmospheric is common; and, it is also usual, after the canned goods have been subjected to the cooking process in one machine, to transfer them to a separate cooler, which is under atmospheric pressure.

As far as I am aware, cooking under pressure greater than atmospheric, whether the pressure is the result of a confined fluid heating medium, such as steam, or is due t0 a body of compressed air overlying a liquid heatin -medium, such as water, has been hereto ore conducted in a single chamber in which the goods, relatively slowly rise to the sterilizing temperature, thereb unnecessarily prolonging their time of coo and, as far as I know, the subsequent cooling of the cans has always been efi'ected in a chamber at atmosphenc pressure, which operation especially with goods sterilized under pressure above atmospheric and at relatively high temperature, (such goods, for example, as corn) has the serious disadvantage of causing the seams of the cans to open, and thus ruin their contents. I

One object of my invention is to provide a method ofcooking under pressure, in accordance with which the goods are rapidly raised to the sterilizing temperature,'and are then held constant at said temperature for the required duration of cook, thereby economizing time.

Another object is to provide a method of sterilizing according to which the goods are cooked under pressure and are cooled under pressure without having been relieved from pressure between the cooking and cooling; thereby avoiding the tendency of the cans to open their scams or burst.

A third object is to provide a method comprising both features above stated in one continuous operation. q

The nature of my inventlon W111 fully appear from the following description in con-.

nection with the accompanying drawings which illustrate an apparatus in which my method may be carried out.

No claims are herein made to this apparatus, as it forms the subject-matter of a separate applicationvfiled contemporaneously herewith under date of September 29, 1920,

and Serial Number 413,587.

In these drawings- Fig. 1 is a side view, broken, and partly 'in vertical longitudinal section, of the ap- Fig. 5 is a top plan view of a detail showing the cuts in the helical guide rail to admit the cans from the feed valve to thereel.

Fig. 6 is a sectional detail on the line 66 of Fig. 1. v

'The apparatus here shown is a box or shell in which the can path is, in general, of a type now well known and comprises a fixed helically directed rail, and a rotating reel of rails inside the helical rail and parallel with its axis. The reel rails are of some type of angle section so that when properly relatively disposed, they and the'helical rail form a continuous helical path through which the cans are conveyed positively from the inlet to the outlet. I

1 is the box or shell fluid-tight and adapted to receive and confine the media required to impart the necessary temperatures and pressures at the several stages of'operation, 'as

will be presently described.

Within the shell in its region of inner cirv Fixed upon this shaft are three pairs of spaced spiders 4, each pair carrying between their rims the circumferentially disposed spaced reel rails 5, thereby forming three reels, rotating in unison, the rails of the reels being alined. These rails are best of anglesection and they lie and rotate within the helically directed rail 2,in such relation thereto that a can introduced at one end of the shell will lie between the rails and will be directed thereby, by the rotation of the reels, throughout a continuous helical path to the other end of the shell.

Within the shell are two partitions 6, Fig. 1. These occupy the full cross section of the shell, except at the upper portion, where as shown in Figs. 1 and 2, they terminate short of the upper arc of theshell, thereby forming three distinct compartments, which in Fig. 1 I have, for convenience, indicated by A, B and C, said compartments successively communicating over the tops of the partitions.

In order to make the can path as long as possible, the general pitch of the helically directed fixed rail 2 is at a relatively slight angleas indicated in Fig. 3, but as it is requlred that the can be advanced from one compartment to the other over the top of the partition, it is necessary in the short time the can is in this upper position, to move it more rapidly, so that it may safely cross the partition. Therefore, the pitch of'the fixed rail, in the region over the partitions, is accelerated materially, as is indicated at 2' in Figs. 1 and 3, whereby the can is moved rapidly through the communications between the compartments, thus conforming the time to the space available.

In Figs. 1 and 4, I have shown a simple form of fluid tight feed valve, comprising a rotatin pocket wheel 7 housed in a shell 8, with w ch a feed chute 9 communicates. This housin communicates with the rotating reel rails o compartment A, the .cans indicated by 10,,in Fig. 4 successively dro ping from the pockets oi the valve wheel 2, through a cut out portionat 11, shown in Fig. 5, of the fixed rails 2, onto the reel rails 5 successively.

Similarly, I have shown in Figs. 1 and 6 a fluid tight discharge valve comprising a pocket wheel 12 in a housing 13 from which a chute 14 leadsFig. 6. The cans 10 are delivered to the pockets of the valve wheel 12 by being lifted from their reel rails 5 by the usher teeth 15 of a pair of rota disks 16. ese disks are rotated gear-wise y the engagement of their teeth with the rails of the rotating reel, as seen in Fig. 6.

In the compartments or regions A and B is a heating medium. This is here indicated by a body of water a in compartment A, and a body of water 5 in compartment B. These water bodies are heated by rforated steam pipes 17 and 17 rospectiv y. Incompartnot shown, and from this shaft, by a gear train 21 on one end, the feed valve-wheel 7 is driven, and by a gear'train 22-on the other end the discharge valve 12 is driven.

In carrying out my method, I first establish a predetermined pressure in the shell by means of the air introduced, and I raise the temperature in compartment A to a degree predetermined by length of time the cans take to pass through said compartment and the' degree of heat required for the sterilization of their contents. The temperature of this initial region, in general terms, should be higher than that required for sterilization, in order to rapidly raise the temperature of the ,can contents to the required degree; and as this temperature is reached the cans are ready to pass into the next heat region or compartment B. In this latter region, the sterilizing temperature is maintained constant throughout the course of the cans therethrough, so that by the time the cans are passing into the third compartment or region C, their time of cook is complete. In this region C, a cooling.

temperature is maintained until, as the cans are discharged they are sufliciently cooled. Thus in all three regions the temperature diflers and though these regions communicate and form a single integral inclosure, all are.

under the same pressure, which serves the double purpose of preventing the interchange of heat between the communicating regions, and of keeping the cans under pressure during the cooling effect.

As a concrete example of my method I give the following: Taking canned corn as the commodity to be sterilized, I would maintain a gauge pressure of sa 20 pounds in the shell. In region A I woulddi 260 degrees F. and would raise the temperature o the cans in'said region to 255 degrees F. in about seven or eight minutes. In region B I would maintain a temperature of 255 degrees F. during the entire travel of the cans therethrough; and in region C, I would have a cooling temperature of say 100 degrees F. or, less. This is merely b way of 1llustration, as difierent comm ties will require different pressures and temperatures.

. I claim 1. The method of sterilizing canned goods which comprises introducing them initially to a region in which the tem rature is higher than t at required for ster' ization and keepave a temperature of i ing them therein until they have been raised to said sterilizing temperature; and then at once transferring them into a second region communicating with the first region and in which the temperature is maintained constant at that required for sterilization and keeping them therein until sterilized.

2. The method of sterilizing canned goods which comprisesintroducing them initially to a region in which the temperature is higher than that required for sterilization and keeping them therein until they have been raised to said sterilizing temperature; and then at once transferring them into a second region communicating with the first region and in which the temperature is maintained constant at that required for sterilization and keeping them therein until sterilized, both regions being under pressure higher than atmospheric. :0 3. The method of sterilizing canned goods which comprises introducing them initially to a region in which the temperature is higher than that required for sterilization and keeping them thereimuntil they have been raised to said sterilizing temperature; and then at once transferring them into a second region communicating with the first'region, and in which the temperature is maintained at that required for sterilization and keeping them therein until sterilized, the transfer of heat from one region to the other through their communications being prevented.

4. The method of sterilizing canned goods which comprises introducing them initially to a region in which the temperature is higher than that required for sterilization and keeping them therein until they have been raised to said sterilizing temperature; and then at once transferring them into a second region communicating with the first region and in which the temperature is maintained at that required for sterilization and keeping them therein until sterilized, both regions bein under pressure higher than atmospheric, an the transfer of heat from one region to the other through their communication being prevented by said pressure.

5. The method of sterilizing canned goods which comprises introducing them initially to a region in which the temperature is higher than that required for sterilization and keeping them therein until they have been raised to said sterilizing temperature; then at once transferring them into a second re 'on communicating with the first region an in which the temperature is maintained at that required for sterilization and keeping them.

therein until sterilized; supplying the heat to both regions through a heated liquid 69 medium; and establishing fluid pressure in both regions on said liquid medium, whereby interchange of heat between the regions is prevented.

"'consisting in introducing the goods initially to a region in which the temperature is higher than that required for steri ization and keeping them therein until they have been raised to said sterilizing temperature; then at once transferring them into a second region communicating with the first region and in which 1 the temperature is maintained at that re-- quired for sterilization and keeping them therein until sterilized; and then at once transferring them into a third region communicating with the second region and in which a cooling tem erature is maintained, all of said regions bemg kept under pressure above atmospheric and said pressure utilized to prevent interchange of heat between the reglons.

7 The method of sterilizing canned goods consisting in introducing the goods initially to a region in which a temperature higher than that required for sterilization is supplied by a heated liquid medium included in said region and keeping them therein until they have been raised to said sterilizing temperature; then at once transferring them into a secon region communicating with region; and maintaining fluid pressure above atmospheric within each region whereby interchange of heat between the regions 1s prevented.

8. A process of heat-treating materlals in sealed receptacles which consists in heating liquid in a closed container to a temperature higher than the temperature at which it bolls in the atmosphere surrounding the container, preventing ebullition of the liquid by a fixed gas held under ressure within the container above the liqui passing the sealed receptacles continuously throu h the heated liquid and through a cooling uid within the container while still maintaining said recegacles underthe same pressure of said ed as. b 9. A process of heat treating objects in a fluid tight container divided into a plurality of communicating chambers containing liquid, which consists in maintaining the liquid in different chambers at different temperatures, respectively, maintaining a fixed gas under pressure within said container, in-

troducing objects to be treated into said container, moving said objects throu h the several chambers in succession, there y subjecting them successively to treatment in the liquid of different temperatures, and finally 6. The method of sterilizing canned goodsremoving the treated objects from the container.

10. The process of heat-treating materials in sealed receptacles which consists in heating said sealed receptacles in a liquid bath within a fluid tight container, said bath being heated to a temperature higher than the temperature at which the liquid boils in the atmosphere surrounding the container, preventing ebullition of the liquid by a fixed gas held under pressure within the container above the liquid, and cooling the sealed receptacles within the container while still maintaining them under the same pressure of the said fixed as.

11. The metho of sterilizing canned goods consisting in introducing the goods initially to a region in which the temperature is higher than that required for sterilization and keeping them therein until they have been raised to such temperature; then at once transferring them into a second region communicating with the first region and in which thetem erature is maintained at that reuired or sterilization and keeping them t erein at such temperature until they are sterilized; and then at once transferring them into a third region communicating with the second region and in which a cooling temperature is maintained.

In testimony whereof I have signed my name to this specification.

. ALBERT R. THOMPSON. 

